Preheat the oven to 160 degrees. Fit the baking sheet with parchment paper, set aside. Mix together the flour, baking powder and salt in a bowl, set aside. Beat butter and sugar in a bowl with an electric mixer at medium speed, about 3 minutes. Add eggs and vanilla, beaten. Reduce the speed and gradually add flour mixtures. Add pears, pistachios and candied ginger, mix. Pour the dough into the prepared form. Bake for about 50 minutes. Let cool on the grill for 15 minutes. Put on the grate and allow to cool completely. Slice into slices. Cookies can be stored in airtight containers at room temperature for up to 3 days.